Image Caption: STS049-75-43 Great Barrier Reef, Queensland, Australia May 1992Two separate reef zones are visible in this northeast view of the northern end of the Great Barrier Reef. The distinct, gently curving arc of the almost unbroken eastern line of coral barrier reefs stands out in contrast to the more randomly spaced coral colonies located on the shallow continental shelf off of the northeast tip of the Cape York Peninsula. This particular image of the Great Barrier Reef shows less than 5 percent (approximately 70 miles--113 kilometers--from the top edge of the frame to the bottom right corner) of the total latitudinal distance that the reef covers along the northeast coast of Queensland. The reef stretches from north-northwest to southeast for 1250 miles (2010 kilometers).